BEIJING - Professor Luo Shu-Jin and her students from Peking University are rooting about in the bush in Yanqing district on the outskirts of Beijing, looking for signs of animal droppings.
In the distance looms the alpine skiing slopes of the Winter Olympics, white and gleaming in the sun - ready for the Games that will be held next month under some of the most stringent Covid-19 control measures.
But unlike the athletes, the creature Prof Luo is looking for would be able to slink in and out of Olympic venues as it pleases.
There are signs of it everywhere in the scrubland near the Guanting reservoir - droppings along the trail, and in the underbrush, the remains of a meal of pheasant - and Prof Luo is looking for a spot to set her trap.
Her quarry is the leopard cat, an elusive ambush predator no bigger than a house cat.
This winter, Prof Luo, an expert in feline genomics, and a team of researchers from the university have been catching these wild cats and fitting them with GPS collars to study how these animals live, hunt and survive so close to one of the world's largest megacities.
They have discovered, for instance, that the cats really "enjoy" swimming, dipping into the freezing water at the nearby wetlands daily, even in the winter.
Diverse range of wildlife
Beijing is one of the few major capital cities with a species of wild cat - which experts say shows the city is home to a diverse range of wildlife - yet little is known about how these animals live in a metropolis of over 20 million people.
"The fact that a megacity like Beijing actually has wild leopard cats living so close to people is really interesting," said Prof Luo.
The area where she has trapped the cats is about 3km from the nearest village and surrounded by farmland.
"We want to understand how these animals can survive in the periphery of such a big city, how they can survive in a human-dominated landscape, and not just survive but appear to be doing quite well."
Leopard cats are one of the most widely distributed wild cats in continental Asia - found in countries ranging from China, to Singapore and India.
In Beijing, they are the only remaining species of wild cat after leopards disappeared about 20 years ago because of habitat loss and hunting. But researchers are not sure how many of these animals live in and around the Chinese capital.
Prof Luo began studying the leopard cats about three years ago, when she noticed them appearing in pictures taken by infrared camera traps she set up on a hiking trail she frequented in Beijing's Yanqing district near the border with Hebei province.
Led by Prof Luo, the new study on these wild cats is being done in collaboration with the China Felid Conservation Alliance, a non-governmental organisation.
Though they are small, the leopard cat sits at the top of its food chain - preying on animals like rodents, rabbits, wild pheasants and small birds - and its presence is a sign that there are healthy populations of prey animals, said Prof Luo.
"If the leopard cat can survive, it also means animals like badgers, wild pigs can also survive… it tells you that this forest or ecosystem they live in is one that has vitality," she said.
Conservationists say the presence of the leopard cat points to a little known fact about Beijing - that it is also home to an array of wildlife.
"Most people hear the word Beijing and think of a very busy city, noise pollution, air pollution, but there's another side to Beijing, which is perhaps a little bit more surprising to most people," said Beijing-based conservationist Terry Townshend.
'Being aware of what you have'
Beijing's sprawling size, encompassing mountains, wetlands and grasslands in its periphery provides homes for a multitude of species, he added. The city has more butterfly and dragonfly species than the whole of Britain.
It also sits on a major flyway for migratory birds, and has recorded about 510 different species of birds, ranking second among Group of 20 capital cities - behind Brasilia, said Mr Townshend, a fellow at the Paulson Institute.
And studies like Prof Luo's play a crucial role in helping raise awareness of what precious nature there is to protect, he added.
"The first step towards successful conservation is being aware of what you have," he said.
"The more Beijingers are aware of what they have in their city, both the cats, the birds and everything else, the more they'll be proud of it and want to protect this biodiversity."
Said Prof Luo: "Our long-term hope is that if the ecology and environment can (recover) to support bigger food chains, perhaps one day we could even see the North China leopard return to Beijing."